1. Introduction
This invention pertains to an intravaginal anchoring device that is inserted into the vagina of a mammalian female.
2. Description of the Prior Art
It has been known for some time that the insertion of devices into the reproductive tract of a farm animal can be an effective means to effect changes in biological processes of the animal. An early device commercially available for non-surgical intravaginal implantation is a progesterone-soaked sponge or pessary insert designed for estrus and ovulation control. J. Sreenan, "Retention of Intravaginal Sponge Pessaries by Cattle", Vet. Rec. 94:45-47 (1974). Later, a device known as PRID, consisting of rings of Silastic tubing, was used to introduce progesterone into the vagina of a mammalian female by impregnating the rings with progesterone. J. F. Roche, "Retention Rate in Cows and Heifers of Intravaginal Silastic Coils Impregnated with Progesterone", J. Reprod. Fert. 46:253-255 (1976). A similar device comprises a vaginal ring formed by covering a stiff metal spring in the form of a closed loop with a silicon polymer. This device is also used to introduce progesterone intravaginally in mammalian females. D. R. Mishell, Jr. et al, "Contraceptive Effect of Varying Dosages of Progestogen in Silastic Vaginal Rings", Fertility and Sterility 21:99-103 (1970).
Devices intended for intravaginal implantation are also described in the patent literature. One such device is known commercially as "HEI-GRO" and is disclosed in U.S. Pat. No. 4,091,807. This device is provided with a central shaft that carries axially-spaced mounting rings to which are affixed elongated rods having bulbous ends. The device is inserted intravaginally to stimulate growth. A similar but improved device is disclosed in U.S. Pat. Nos. 4,387,724 and 4,377,157.
U.S. Pat. Nos. 3,811,423 and 3,811,424 disclose a complicated intravaginal anchoring assembly that comprises a plurality of resilient spring-like strands configured in the shape of hoops and disposed around a housing. The strands are mounted in such fashion as to be collapsible under certain conditions, whereupon the device is projected into a sensitive area of the vagina and subsequently expulsed from the animal by peristaltic movement. In one embodiment, the strands are formed into hoops by moving two rings, to which ends of the strands are attached, toward each other, while at the same time preferably rotating one of the rings relative to the other. The duration of the period of retention of the device in an animal's vagina is determined by the contacting and dissolution of an element of the device by ovulation precursive fluids.
Unfortuantely, the intravaginal devices of the prior art have failed to provide an anchoring means that is suitable for use in a variety of applications. In particular, the prior art has failed to provide an intravaginal anchoring device that is easily inserted, appropriately retained for a desired period, and easily removed, and which does not interfere with the normal functioning of the host organ. Further, many of the devices of the prior art are complicated in design and others are unsuitable for accomodating instrument packages that can be applied to identify an animal or monitor or effect biological processes.
Accordingly, it is an object of the present invention to provide an intravaginal anchoring device that is easily inserted into the vagina of a mammalian female and, once inserted, readily retained for the period of retention prescribed in accordance with the particular application for which the device has been inserted, including applications requiring long-term retention.
It is a further object of the invention to provide an intravaginal anchoring device that does not impair the flow of fluids and secretions through the recipient animal's vagina during the period of retention.
It is a further object of the invention to provide an intravaginal anchoring device that is not detrimental to the health of the animal or its natural physiological processes.
It is a further object of the invention to provide an intravaginal anchoring device that does not prevent insemination during the period of retention.
It is a further object of the present invention to provide an intravaginal anchoring device that is capable of carrying an instrument package, a nutriment package, or a medicinal package while being retained in the vagina of a mammalian female.
It is a further object of the invention to provide an intravaginal anchoring device that is capable of carrying an instrument package that is impervious to fluids that are found within the reproductive tract.
It is a further object of the invention to provide an an intravaginal anchoring device that is simple in construction and inexpensive to manufacture.
It is a further object of the invention to provide an intravaginal anchoring device that is relatively small in size, such that is more acceptable and more comfortable for the recipient animal.
It is a further object of the invention to provide an intravaginal anchoring device that is streamlined in construction, such that it is more easily handled, inserted and removed.
It is a further object of the invention to provide an intravaginal anchoring device that maintains a predictable position with the vagina of a mammalian female, such that the antenna of an electronic communications device disposed within an instrument package carried by the device can be optimally disposed relative to an exterior transmitting or receiving station.
It is a further object of the invention to provide an intravaginal anchoring device that is suitable for use in a variety of mammalian females without redesign, but instead by merely altering dimensions of the device.
A still further object of the invention is to provide an intravaginal anchoring device that is easily removed manually or, in certain applications, by natural biological processes such as fetal delivery by the recipient animal, when the prescribed period of retention is intended to be terminated.
Other objectives of the present invention will be apparent from the following detailed description of the preferred embodiments.